Mechanisms and protective measures for radiation-induced brachial plexus nerve injury.

Radiation therapy is a common treatment modality for patients with malignant tumors of the head and neck, chest and axilla. However, radiotherapy inevitably causes damage to normal tissues at the irradiated site, among which damage to the brachial plexus nerve(BP) is a serious adverse effect in patients receiving radiation therapy in the scapular or axillary regions, with clinical manifestations including abnormal sensation, neuropathic pain, and dyskinesia, etc. These adverse effects seriously reduce the living quality of patients and pose obstacles to their prognosis. Therefore, it is important to elucidate the mechanism of radiation induced brachial plexus injury (RIBP) which remains unclear. Current studies have shown that the pathways of radiation-induced BP injury can be divided into two categories: direct injury and indirect injury, and the indirect injury is closely related to the inflammatory response, microvascular damage, cytokine production and other factors causing radiation-induced fibrosis. In this review, we summarize the underlying mechanisms of RIBP occurrence and possible effective methods to prevent and treat RIBP.

Brachial plexus birth injuries: a multi-speciality approach. Commentary and opinions.

The management of brachial plexus birth injuries (BPBI) remains controversial and ever evolving. In this article, studies are examined to provide further insight into the ongoing controversies and debates surrounding BPBI. The articles are diverse and examine the topics of aetiology, demographics, reliability versus accuracy of measurements and surgical management. The management of BPBI may differ depending on resources. Outcome measures may also vary depending on geography. Future research should focus on developing consensus-validated measures and reproducible surgical techniques. These can then guide further population-based research and provide guidelines to minimize the incidence of BPBI.

Brachial plexus birth injury: advances and controversies.

While there is considerable spontaneous recovery in most cases of brachial plexus birth injury, many children are left with significant problems that may lead to lifelong functional limitations, loss of work and social isolation. Detailed treatment with the right strategy can provide very valuable improvement in function. Over the past few years, the clinical approach to brachial plexus birth palsy has entered a new era in both diagnostic and surgical treatment methods. This article reviews four areas of management, the role of imaging in defining the severity of the injury, the optimal timing of for nerve exploration and reconstruction in appropriate cases, the advantages and potential complications of nerve transfers, and the role of physiotherapy. Available evidence is considered. Although it is difficult to make clear and precise inferences on a subject where there are many variables and considerable uncertainties, some currently accepted views will be summarized.Level of evidence: V.

Hypofractionated Stereotactic Radiation Therapy Dosimetric Tolerances for the Inferior Aspect of the Brachial Plexus: A Systematic Review.

We sought to systematically review and summarize dosimetric factors associated with radiation-induced brachial plexopathy (RIBP) after stereotactic body radiation therapy (SBRT) or hypofractionated image guided radiation therapy (HIGRT). From published studies identified from searches of PubMed and Embase databases, data quantifying risks of RIBP after 1- to 10-fraction SBRT/HIGRT were extracted and summarized. Published studies have reported <10% risks of RIBP with maximum doses (Dmax) to the inferior aspect of the brachial plexus of 32 Gy in 5 fractions and 25 Gy in 3 fractions. For 10-fraction HIGRT, risks of RIBP appear to be low with Dmax < 40 to 50 Gy. For a given dose value, greater risks are anticipated with point volume-based metrics (ie, D0.03-0.035cc: minimum dose to hottest 0.03-0.035 cc) versus Dmax. With SBRT/HIGRT, there were insufficient published data to predict risks of RIBP relative to brachial plexus dose-volume exposure. Minimizing maximum doses and possibly volume exposure of the brachial plexus can reduce risks of RIBP after SBRT/HIGRT. Further study is needed to better understand the effect of volume exposure on the brachial plexus and whether there are location-specific susceptibilities along or within the brachial plexus structure.

Brachial plexopathy after breast cancer: A persistent late effect of radiotherapy.

Radiation-induced brachial plexopathy (RIBP) is an iatrogenic, progressively disabling, and often very late effect of adjuvant radiotherapy most commonly seen in breast cancer survivors but also in those treated for lymphoma, lung, and head and neck cancers. In late-onset RIBP following breast cancer, the nerve injury is chronic and irreversible, occurring more commonly when axillary and/or supraclavicular nodes have been irradiated, as well as the breast/chest wall. RIBP is manifested initially by paresthesia, hypoesthesia, dysesthesia, and later by weakness in the ipsilateral hand with those symptoms progressing distally to proximally up through the shoulder. Depressed/absent deep tendon reflexes in the upper extremity and muscle fasciculations occur also. Neither patients nor their health care providers tend to associate these unusual neurological symptoms with cancer treatments received ≥20 years prior, often failing to link these sensory-motor symptoms with radiotherapy decades before. Because long-term follow-up of these patients now typically falls to general practitioners, many cases may be missed or misdiagnosed because of the rarity of this disorder. Physiatrists and allied rehabilitation professionals must be aware of this progressively disabling, incurable condition to provide appropriate diagnoses and compensatory rehabilitation therapies. Additionally, professional oncology organizations should include RIBP in their long-term, survivorship guidelines for breast cancer. Researchers examining the iatrogenic late effects of radiotherapy should extend their follow-up periods well beyond the current 5-6 years to ascertain the true incidence of RIBP today. Rehabilitation providers must continue to advocate for awareness, diagnosis, and management of iatrogenic outcomes experienced by long-term cancer survivors.

Dosimetric analysis of brachial plexopathy after stereotactic body radiotherapy: Significance of organ delineation.

OBJECTIVES: Examine the significance of contouring the brachial plexus (BP) for toxicity estimation and select metrics for predicting radiation-induced brachial plexopathy (RIBP) after stereotactic body radiotherapy. MATERIALS AND METHODS: Patients with planning target volume (PTV) ≤ 2 cm from the BP were eligible. The BP was contoured primarily according to the RTOG 1106 atlas, while subclavian-axillary veins (SAV) were contoured according to RTOG 0236. Apical PTVs were classified as anterior (PTV-A) or posterior (PTV-B) PTVs. Variables predicting grade 2 or higher RIBP (RIBP2) were selected through least absolute shrinkage and selection operator regression and logistic regression. RESULTS: Among 137 patients with 140 BPs (median follow-up, 32.1 months), 11 experienced RIBP2. For patients with RIBP2, the maximum physical dose to the BP (BP-Dmax) was 46.5 Gy (median; range, 35.7 to 60.7 Gy). Of these patients, 54.5 % (6/11) satisfied the RTOG limits when using SAV delineation; among them, 83.3 % (5/6) had PTV-B. For patients with PTV-B, the maximum physical dose to SAV (SAV-Dmax) was 11.2 Gy (median) lower than BP-Dmax. Maximum and 0.3 cc biologically effective doses to the BP based on the linear-quadratic-linear model (BP-BEDmax LQL and BP-BED0.3cc LQL, α/ß = 3) were selected as predictive variables with thresholds of 118 and 73 Gy, respectively. CONCLUSION: Contouring SAV may significantly underestimate the RIBP2 risk in dosimetry, especially for patients with PTV-B. BP contouring indicated BP-BED0.3cc LQL and BP-BEDmax LQL as potential predictors of RIBP2.

Key Considerations for Nerve Transfer Rehabilitation After Surgical Reconstruction for Brachial Plexus and Peripheral Nerve Injuries.

Nerve transfer surgery is commonly used to treat patients with brachial plexus injuries. However, guidelines on postoperative rehabilitation are not clearly established. Nerve transfers require the patient to relearn how to recruit newly innervated muscle(s), which may not occur naturally or intuitively. Supervised therapy is a valuable resource to guide patients through their lengthy recovery (often >12 months) because target muscle strength is both obtained and functionally used in daily life. This article highlights 10 key principles that provide the foundation for rehabilitation following nerve transfer surgery after a brachial plexus injury. Due to the shortcomings of the current evidence base for nerve transfer rehabilitation, we have included our anecdotal experience to augment the existing literature. It is important to have a collaborative surgeon-therapist relationship to communicate regarding operative details, expected timelines for reinnervation, patient needs, and realistic expectations. We provide examples of how to tailor the exercise program to synergistically recruit both the donor and target muscle action, including how to appropriately advance exercises based on the current level of nerve return. We also discuss the role that fatigue plays in denervated muscle and how fatigue may affect the exercise demands placed on the target muscle during specific stages of recovery.

Is it possible to follow the risk of rupture after end-to-end nerve repairs in brachial plexus surgery? Technical note.

OBJECTIVE: In traumatic and obstetric brachial plexus injuries, removal of the damaged nerve, repair with the nerve grafts, and nerve transfers are mostly preferred techniques. Success is directly proportional to surgical technique as it is known that end-to-end repair of the peripheral nerves gives better results. The greatest risk in end-to-end repair is the nerve rupture at the brachial plexus repair region and this cannot be detected by conventional radiological techniques. METHODS: Brachial plexus injuries of obstetrical and traumatic patients were operated. If possible and at least one nerve was repaired end to end, follow-up of nerve continuity was done by titanium hemopclip insertion to both sides of the nerve repair area. A new technique nerve repair site marking was developed and end-to-end nerve repair continuity was followed simply by x-ray. RESULTS: This technique was used for end-to-end nerve coaptions of 38 obstetric and 40 traumatic brachial plexus injuries. Follow-up was done for 6 weeks. Every week patients sent the x-ray of the repair site. Only 3 patients had nerve repair site rupture, and revision surgery was done immediately. CONCLUSION: Nerve repair site marking technique and follow-up with only x-ray is a simple reliable, safe, and cheap method that can be applied to any end-to-end nerve repair. This technique has no morbidity or side effects. The aim of the study is to summarize or explain the nerve repair site marking technique used in the brachial plexus region.

Recent Advances in the Treatment of Brachial Plexus Birth Injury.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe methods of clinical evaluation for neurologic recovery in brachial plexus birth injury. 2. Understand the role of different diagnostic imaging modalities to evaluate the upper limb. 3. List nonsurgical strategies and surgical procedures to manage shoulder abnormality. 4. Explain the advantages and disadvantages of microsurgical nerve reconstruction and distal nerve transfers in brachial plexus birth injury. 5. Recognize the prevalence of pain in this population and the need for greater sensory outcomes evaluation. SUMMARY: Brachial plexus birth injury (BPBI) results from closed traction injury to the brachial plexus in the neck during an infant's vertex passage through the birth canal. Although spontaneous upper limb recovery occurs in most instances of BPBI, some infants do not demonstrate adequate motor recovery within an acceptable timeline and require surgical intervention to restore upper limb function. This article reviews major advances in the management of BPBI in the past decade that include improved understanding of shoulder pathology and its impact on observed motor recovery, novel surgical techniques, new insights in sensory function and pain, and global efforts to develop standardized outcomes assessment scales.

Diagnostic value of proximal cutaneous nerve biopsy in brachial and lumbosacral plexus pathologies.

BACKGROUND: Brachial and lumbosacral plexopathies can result from numerous non-traumatic etiologies, including those of inflammatory, autoimmune, or neoplastic origin, that often require nerve biopsy for diagnosis. The purpose of this study was to evaluate the diagnostic efficacy of medial antebrachial cutaneous nerve (MABC) and posterior femoral cutaneous nerve (PFCN) nerve biopsies in proximal brachial and lumbosacral plexus pathology. METHOD: Patients undergoing MABC or PFCN nerve biopsies at a single institution were reviewed. Patient demographics, clinical diagnosis, symptom duration, intraoperative findings, post-operative complications, and pathology results were recorded. Biopsy results were classified as diagnostic, inconclusive, or negative based on the final pathology. RESULTS: Thirty patients undergoing MABC biopsies in the proximal arm or axilla and five patients with PFCN biopsies in the thigh or buttock were included. MABC biopsies were diagnostic in 70% of cases overall and 85% diagnostic in cases where pre-operative MRI also demonstrated abnormalities in the MABC. PFCN biopsies were diagnostic in 60% of cases overall and in 100% of patients with abnormal pre-operative MRIs. There were no biopsy-related post-operative complications in either group. CONCLUSIONS: In diagnosing non-traumatic etiologies of brachial and lumbosacral plexopathies, proximal biopsies of the MABC and PFCN provide high diagnostic value with low donor morbidity.

The effect of botulinum toxin application on latissimus dorsi and teres major muscles in patients with brachial plexus birth palsy: An electron microscopic and clinical study.

BACKGROUND: In brachial plexus birth palsy (BPBP), botulinum toxin may be utilized to prevent glenohumeral dysplasia and to maintain the stable growth of the glenohumeral joint. Repeated injections may cause muscular atrophy and their functional effects are uncertain. The aim of this study was to compare the microstructure and the function of the muscles that received two injections before transfer with the muscles that were not injected. METHODS: BPBP patients that were operated between January 2013 and December 2015 were included in the study. Latissimus dorsi and teres major muscles were transferred to humerus in standard fashion. Patients were divided in two groups according to bo-tulinum toxin status. Group 1 was toxin negative whereas Group 2 was toxin positive. For each patient, mean latissimus dorsi myocyte thickness (LDMT) was measured with electron microscopy and pre-operative and post-operative active shoulder abduction, flexion, external and internal rotation, and Mallet scores were evaluated with goniometry. RESULTS: Fourteen patients (seven patients per group) were evaluated. Five patients were female whereas nine were male. Mean LDMT was not affected significantly (p>0.05). The operation improved shoulder abduction, flexion, and external rotation significantly (p<0.05), independent of the toxin status. The internal rotation decreased significantly only in Group 2 (p<0.05). The Mallet score increased in both groups, but it was not significant (p>0.05), independent of the toxin status. CONCLUSION: Botulinum toxin that was applied twice prevented glenohumeral dysplasia and it did not cause permanent latissimus dorsi muscle atropy and function loss in late period. It augmented upper extremity functions by alleviating internal rotation contracture.

Brachial Plexus Birth Injury: A Single-Center Study.

Infants can sustain traction injury to brachial plexus nerves during birth, called brachial plexus birth injury (BPBI). While spontaneous recovery is possible, upper extremity weakness can linger. We report our experience at a brachial plexus clinic from a retrospective chart review of infants with BPBI from September 2017 to September 2019. We determined Narakas Classification (NC) and Active Movement Scale (AMS) at predetermined follow-up points. Of 15 patients, 8 presented with NC-I, 5 with NC-II, and 2 with NC-III without Horner's syndrome. By 7 months, 3 had spontaneous recovery, and 4 achieved all and another 4 achieved most AMS5-7 scores. Eleven patients undergoing surgery had little-to-no improvement of shoulder abduction and shoulder external rotation AMS categories by 6 months. Our small sample size prevents us from making definitive conclusions but gave beneficial insight into our clinic barriers to follow-up, data collection, and collaboration with physical and occupational therapy.

Static and Dynamic Stabilization of the Shoulder After Total Scapulectomy in an Electric Burn Patient.

ABSTRACT: An otherwise healthy 49-year-old man experienced a high-voltage electrical injury to the left shoulder resulting in total scapulectomy, partial calviculectomy, and a substantial soft tissue defect. The majority of the muscles around his shoulder were debrided because of necrosis, with only the pectoralis and latissimus dorsi muscles remaining attached to the humerus. Surprisingly, the patient's brachial plexus remained intact, and his left elbow, wrist, and hand function were preserved. A novel combination of 3 static and dynamic suspension techniques were used to stabilize his shoulder and prevent traction injury to the brachial plexus. Postoperative follow-up at 1 year demonstrated excellent stability of his reconstructed shoulder, which allowed him to ambulate independently and return to employment.

Radiation-induced inferior brachial plexopathy after stereotactic body radiotherapy: Pooled analyses of risks.

INTRODUCTION: Radiation-induced brachial plexopathy (RIBP), resulting in symptomatic motor or sensory deficits of the upper extremity, is a risk after exposure of the brachial plexus to therapeutic doses of radiation. We sought to model dosimetric factors associated with risks of RIBP after stereotactic body radiotherapy (SBRT). METHODS: From a prior systematic review, 4 studies were identified that included individual patient data amenable to normal tissue complication probability (NTCP) modelling after SBRT for apical lung tumors. Two probit NTCP models were derived: one from 4 studies (including 221 patients with 229 targets and 18 events); and another from 3 studies (including 185 patients with 192 targets and 11 events) that similarly contoured the brachial plexus. RESULTS: NTCP models suggest ≈10% risks associated with brachial plexus maximum dose (Dmax) of ∼32-34 Gy in 3 fractions and ∼40-43 Gy in 5 fractions. RIBP risks increase with increasing brachial plexus Dmax. Compared to previously published data from conventionally-fractionated or moderately-hypofractionated radiotherapy for breast, lung and head and neck cancers (which tend to utilize radiation fields that circumferentially irradiate the brachial plexus), SBRT (characterized by steep dose gradients outside of the target volume) exhibits a much less steep dose-response with brachial plexus Dmax > 90-100 Gy in 2-Gy equivalents. CONCLUSIONS: A dose-response for risk of RIBP after SBRT is observed relative to brachial plexus Dmax. Comparisons to data from less conformal radiotherapy suggests potential dose-volume dependences of RIBP risks, though published data were not amenable to NTCP modelling of dose-volume measures associated with RIBP after SBRT.

Outcome of Nerve Grafting for Radiation-Induced Brachial Plexopathy.

BACKGROUND: There is no consensus on the optimal treatment for radiation-induced brachial plexopathy (RIBP). OBJECTIVE: To present our experience of using nerve resection and autografting as a treatment strategy for this challenging condition. METHODS: From September 2014 to January 2020, 8 patients with RIBP were treated with segmental nerve resection and autografting, with or without other supplementary procedures. All patients underwent sural nerve grafting to the musculocutaneous nerve. All were female with a mean age of 53 (range 38-64) years. Seven were on the left, and 1 was on the right. The mean follow-up duration was 33 (range 17-72) months. RESULTS: By the final review, 7 of 8 patients regained at least antigravity elbow flexion. Four patients reached Medical Research Council (MRC) grade 4, 3 MRC grade 3, and MRC grade 2 recovery in the biceps. The mean Visual Analog Score for pain improved from 2.6 preoperatively to 0.6 postoperatively ( P = .042). CONCLUSION: Nerve resection and autografting may restore satisfactory elbow flexion in patients with RIBP.

Brachial Plexopathy After Single-Fraction Stereotactic Body Radiation Therapy in Apical Lung Tumors.

PURPOSE: The objective of this study was to evaluate the incidence of brachial plexus injury (BPI) after single-fraction stereotactic body radiation therapy (SBRT) to apical lung tumors. METHODS AND MATERIALS: A retrospective cohort analysis was performed of all patients treated with single-fraction lung SBRT at our institution from 2007 to 2022. Apical tumors were identified as those with an epicenter located above the arch of the aorta. Dosimetric analysis of dose to the brachial plexus (BP) was done using both the subclavian vessel (SCV) surrogate structure and anatomic BP. BPI was assessed per Common Terminology Criteria for Adverse Events, version 4.0, as regional paresthesia, marked discomfort and muscle weakness, and limited movement of the arm or hand. RESULTS: A total of 45 patients met inclusion criteria with median follow-up of 21 months. There were 9 patients who exceeded the BP dose constraint using the SCV or anatomic BP volume. Only 1 patient (2.2%) developed grade 2 BPI, occurring 7 months after SBRT. Dose to the anatomic BP for the affected patient was 26.39 Gy. For the entire cohort, the median SCV and anatomic maximum BP doses were 8.44 and 7.14 Gy, respectively. CONCLUSIONS: There is considerable variability in dose delivered to the BP after SBRT to apical lung tumors. BPI after single-fraction SBRT to apical tumors is rare and rates are comparable with those reported with multifraction regimens.

Glenoid osteotomy with various tendon transfers for brachial plexus birth palsy: clinical outcomes.

BACKGROUND: Posterior shoulder dislocation is one of the disabling complications of brachial plexus birth injury (BPBI), and various treatment options including capsule and surrounding muscles release for open reduction, humeral derotational osteotomy, and tendon transfers have been recommended to manage it. In the present study, we aimed to determine the clinical outcome of open reduction with soft tissue release, tendon transfer, and glenoid osteotomy in patients with BPBI and posterior shoulder dislocation or subluxation. METHODS: From 2018 to 2020, 33 patients who underwent open reduction, glenoid osteotomy, and tendon transfer were included. The glenohumeral deformity was classified according to the Waters radiographic classification. Functional assessment was performed using the Mallet grading system before and at least 2 years after the surgery. RESULTS: The patients were monitored for 26.88 ± 5.47 months. Their average age was 27.5 ± 14 months. Significant improvement was seen in the overall Mallet score (from 13.5 to 18.91 points) and its segments including hand-to-mouth, hand-to-neck, global abduction, global external rotation, abduction range of motion (ROM), and external rotation ROM. Hand-to-back score and the presence of a Trumpet sign were significantly decreased in the postoperation phase (all P values < .001). The above-mentioned variables significantly changed for both infantile and noninfantile dislocations. CONCLUSION: Our study demonstrated that open reduction along with glenoid osteotomy improves retroversion, and muscle strengthening with different muscle transfers is an effective technique for BPBI.

[Radiation induced brachial plexopathy: Diagnosis, risk factors, principles of care]. / La plexite radique : épidémiologie, diagnostic, facteurs de risque et prise en charge.

Radiation plexitis, also known as radiation-induced brachial neuropathy is a rare toxicity following axillary, breast, cervical or thoracic radiotherapy, first described in 1966 by Stoll and Andrew. Although improvements in radiotherapy techniques have greatly reduced its risk over the past seventy years, its severe form remains a dreaded complication that is difficult to manage in patients with increased life expectancy. This article summarizes the epidemiological elements, risk factors, diagnostic methods, doses and constraints to be respected in radiotherapy and the treatment strategies of radiation plexitis.

Brachial Plexus Birth Injury: A Review of Neurology Literature Assessing Variability and Current Recommendations.

BACKGROUND: Publications regarding the epidemiology and management of brachial plexus birth injury (BPBI) were evaluated to investigate treatment guidelines for children with BPBI. METHODS: A search of neurology literature from 1990 to 2019 was performed using PubMed, Scopus, and Medline. Data including incidence, risk factors, spontaneous recovery rates, imaging studies, treatment recommendations, and indications and timing for surgery were collected. RESULTS: A total of 46 total studies were reviewed. Reported incidence rates for BPBI ranged from 0.3 to 3 per 1000 births. Spontaneous recovery rates had an average reported range from 66% to 75%. Physical and occupational therapy were recommended in 37% of articles. Computed tomographic myelogram and magnetic resonance imaging of the brachial plexus were the most commonly recommended imaging studies for BPBI. Timelines for surgical interventions ranged from age three to nine months. Early referral was recommended in 28% of the articles included in the review. CONCLUSIONS: Given the inconsistencies in spontaneous recovery rates, imaging recommendations, and timing of referral, establishing consistent clinical guidelines for patients with BPBI is crucial for management. Early referral to specialists for evaluation and treatment may improve outcomes in children with BPBI.